{"id":1872,"date":"2023-12-12T05:00:00","date_gmt":"2023-12-12T13:00:00","guid":{"rendered":"https:\/\/www.angulartraining.com\/daily-newsletter\/?p=1872"},"modified":"2023-12-11T11:36:27","modified_gmt":"2023-12-11T19:36:27","slug":"code-challenge-2-solution","status":"publish","type":"post","link":"https:\/\/www.angulartraining.com\/daily-newsletter\/code-challenge-2-solution\/","title":{"rendered":"Code challenge #2 Solution"},"content":{"rendered":"\n

In yesterday’s code challenge<\/a>, our application wasn’t displaying any data. There were two reasons for that problem:<\/p>\n\n\n\n

    \n
  1. HttpClient<\/code> was not provided in the application<\/li>\n\n\n\n
  2. The change detection strategy<\/a> OnPush<\/code> wasn’t compatible with the data flow of the application<\/li>\n<\/ol>\n\n\n\n

    I’m including links to previous newsletter entries for deeper dives on the different topics involved in that solution. And there are quite a few subtleties to overcome.<\/p>\n\n\n\n

    Let’s tackle the first issue, which was providing the HTTP client. We can use one of the several utility functions for standalone app config<\/a>, in our case, provideHttpClient<\/a><\/code>:<\/p>\n\n\n

    \n
    \"\"<\/figure>\n<\/div>\n\n\n

    <\/p>\n\n\n\n

    The second problem can be solved in two different ways:<\/p>\n\n\n\n

      \n
    1. Remove change detection onPush<\/code> to use the default<\/code> one instead<\/li>\n\n\n\n
    2. Use the async<\/code> pipe or Signals to trigger change detection<\/a> in that OnPush<\/code> component<\/li>\n<\/ol>\n\n\n\n

      Because it’s always better to use the async<\/code> pipe<\/a>, I’m going with that option in our template:<\/p>\n\n\n

      \n
      \"\"<\/figure>\n<\/div>\n\n\n

      <\/p>\n\n\n\n

      In our component class, I stored the Observable from our service instead of storing the data. No more constructor needed:<\/p>\n\n\n

      \n
      \"\"<\/figure>\n<\/div>\n\n\n

      <\/p>\n\n\n\n

      You can see that solution in action on Stackblitz here<\/a>. We fixed our code and added some performance improvements as well by ensuring we can’t get into memory leaks and optimizing change detection for that component.<\/p>\n","protected":false},"excerpt":{"rendered":"

      In yesterday’s code challenge, our application wasn’t displaying any data. There were two reasons for that problem: I’m including links to previous newsletter entries for deeper dives on the different topics involved in that solution. And there are quite a few subtleties to overcome. Let’s tackle the first issue, which was providing the HTTP client. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,40],"tags":[],"class_list":["post-1872","post","type-post","status-publish","format-standard","hentry","category-angular","category-code-challenge"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts\/1872","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/comments?post=1872"}],"version-history":[{"count":2,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts\/1872\/revisions"}],"predecessor-version":[{"id":1877,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/posts\/1872\/revisions\/1877"}],"wp:attachment":[{"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/media?parent=1872"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/categories?post=1872"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.angulartraining.com\/daily-newsletter\/wp-json\/wp\/v2\/tags?post=1872"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}